The invention is directed to a transmission and reception module for a bidirectional, optical message and signal transmission.
Such transmission and reception modules are known and are disclosed, for example, by EP-A-0 463 214, corresponding to U.S. Pat. No. 5,127,075. Such modules are utilized for bidirectional message or data transmission in full duplex or half duplex operation.
In a transmission and reception module for a bidirectional, optical communication network disclosed by EP-A-0 238 977, corresponding to U.S. Pat. No. 4,767,171, two spherical lenses that focus the laser light onto the fiber end are arranged at a distance from one another essentially between a laser diode and an end of an optical fiber. A light beam separating means or a beam splitter is arranged between the spherical lenses. This beam splitter separates the light divergently beamed from the fiber end in the direction of the transmitter-remote lens. This lens, having a wavelength different from the wavelength of the laser light from the beam path, focuses and conducts the light to a detector or light receiver. In order to avoid a de-adjustment sensitivity of such a module, the laser diode and the lens lying close thereto are fixed relative to one another on a common carrier body so that they are resistant to de-adjustment. At least the laser diode or the light transmitter, the transmitter-proximate lens, the light beam separating means (beam splitter) and the light receiver (detector) are accepted in a housing to which an end of an optical fiber can be connected, this end being arranged in the focus of the light of the one wavelength that is stationarily defined relative to the common housing. The housing is hermetically tight for protection against disturbing environmental influences, particularly of the active semiconductor components (light transmitter and light receiver) accommodated in the housing.